Field of the Invention
This invention is generally directed to loading dock lifts and more specifically to safety barriers for such loading dock lifts.
Background of the Invention
Loading dock lifts have a variety of applications involving the transfer of cargo between an elevated truck bed and a depot floor. A typical loading dock lift includes a lift platform and apparatus for moving the lift platform between an upper position aligned with a truck bed and a lower position in which the lift platform is aligned with the depot floor. Cargo transfers during loading and unloading operations from the truck occur at a “front” side of the loading dock lift which is closely adjacent the truck bed. A “back” side of the lift platform is parallel to and spaced from the “front” side. When the lift platform is at a lowered position, cargo can be transferred between the depot floor and the lift platform at the back side. “Left” and “right” sides of the lift platform extend between the front and back sides of the lift platform, “left” and “right” being referenced when viewing the loading dock lifts from the back side of the lift platform toward the truck.
For purposes of this invention, “cargo” may comprise a variety of goods that have different sizes, shapes and weights. Generally speaking a lift platform is useful in elevating cargo from the depot floor to an upper level corresponding to a truck bed level to facilitate the transfer of freight onto the truck bed. That is, when freight is to be loaded onto a truck, the freight is transferred onto the lift platform over the back side at the ground or factory floor level. Then the lift platform and any cargo loaded on the lift platform elevates until the lift platform comes into an essentially coplanar alignment with the truck bed whereby cargo can transfer to the truck bed past the lift platform front side.
During an off-loading operation, an empty lift platform elevates to be in an essentially vertical alignment with the truck bed whereupon cargo can be moved from the truck bed onto the elevated lift platform past the front side. Then the loaded lift platform lowers to the factory floor level whereupon the cargo can be moved from the lift platform to the depot floor at the back side of the loading dock lift.
Personnel may ride on a loading dock lift during displacement of the lift platform. Consequently it is important that such loading dock lifts minimize the possibility of a person's sustaining an injury by making a misstep and possibly falling from the lift platform in an elevated position.
Many loading dock lifts include fixed side barriers along each side that prevent an individual from inadvertently walking off the lift platform along each side. When the upper surface of a lift platform is coplanar with the factory floor, there is little risk of personal injury by walking past the front side because the front side essentially is at the same level as the factory floor and is adjacent the truck bed. However, when the lift platform is elevated and absent a barrier across the back end of the lift platform, there is greater risk of personal injury due to a misstep because a person could fall along with the cargo being loaded on or off the truck at the back side of the lift platform.
Prior art lift platforms may include a barrier spanning the back side of the lift platform for providing protection during operations while the lift platform is being elevated or lowered or is at the elevated position. A common prior art approach uses a chain or other removable barrier that personnel attach and detach when the lift platform is lowered and attach prior to elevating the lift platform. However, such attaching and detaching steps constitute extra work that personnel may overlook while performing loading and unloading operations even recognizing that a failure to install this barrier poses a risk of injury. Consequently, such barriers along back side the lift platform still pose a risk to personnel of inadvertently walking off the lift platform while it is elevated.